SU1435505A1 - Method of storing toxic brines in permafrost environment - Google Patents

Abstract

The invention relates to the protection of the environment from contamination by liquid waste from mining, chemical and other industries. The goal is to increase the storage efficiency by reducing the capacity of the surface drives and increasing the environmental safety of the storage of toxic brines. The method of storing toxic brines in permafrost conditions includes the collection and accumulation of brines (P) in surface accumulators. Then, preparation of the frozen collector adjacent to the mine workings is concluded. This is carried out by batch injection into the production of P. Then, pumping out P is carried out through the mine working. Injection P is effected below the basis of the surface of the mass before the spreading of P in the mass after they have frozen. In the autumn-winter period. In order to prepare the adjacent array, P is pumped with a concentration equal to the saturation concentration. During the summer period, P heated by atmospheric air are pumped. I zp f-ly, 1 ill. i

Description

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: The invention relates to the protection of the environment from contamination by liquid branches of mining, chemical and other products and can be used for the storage of toxic brines under permafrost conditions. A: The purpose of the invention is to increase the storage efficiency by reducing the capacity of surface storage devices and to increase the environmental reliability of the storage of brines.

 The perception of permafrost as a relatively homogeneous array of semi-rocks, cemented by ice, and completely filling our fractures and pores, which transform this massif into a water-permeable bed below the high-pressure groundwater, is common.

j As a result of studying the permafrost, it was found that in the array of permafrost there are a sufficient number of natural reservoirs (three- and pores) that are not filled with ice and formed as a result of cryogenic effects on the rocks. With an average ice mass of 4%, the total porosity and fracture is 7–9%. Including the effective fracture, which determines the capacity parameters of the bulk: mass, is estimated at 1–1.5%. When storing brines, leaching of ice, cementing the permafrost rock mass, occurs and due to this gradual dilution of brines. Dilution occurs until the | freezing temperature of the diluted brines is equal to the temperature I of the host-permafrost massif. Subsequently, the diluted brines freeze and their spreading in the rocks ceases. At the periphery of the injection site, a constant ice-breed curtain forms, protecting the water-saturated zone. : For injection of brines, select areas that differ by structural: disturbance and located within geological structures that are favorable for removal of the injected rocks from the protected object (for example, folding wings or monoclines with falling into layers in the direction of opposite to the waste generation source).

Aquifer systems are associated with each other.

The drawing shows the scheme of the method.

The drainage of the pit 1 is made possible by the method of open drainage through pipelines 2. Drainage waters temporarily, from November to March (when the air temperature does not exceed -25 ° C), are accumulated in the surface storage tank 3.

The location of the injection site is selected in the depth of development zone: many times

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West-Northwest strike strike. The total fall in rocks of the sedimentary complex is 3-5 ° northwest of the pit. The altitude is the absolute mark of the area of the site above the valleys of the watercourses of the deposit area. The permafrost sole is located directly above the Upper Cambrian aquarium horizon 4. The rocks of the injection site by filterability and ice content are located in zones 5–8, where zone 8 is the monolithic base of permafrost.

For injection of brines into the natural permafrost reservoirs, the forge 9 was excavated in the form of an absorbing well to a depth above the permafrost base. The borehole is in dense rocks, interbedded by thin and rare rock straits. The above section is represented mainly by clayey limestone and marl. To arrange brine injection, the well is equipped with a filter column 10.

From the accumulator, 3 brine is pumped to the mountain absorber, with a yield of 9 by pipeline 11. The brines are pumped into the natural permafrost reservoirs from free run between March and September. Moreover, brines are pumped below the erosion basis 12 to ensure the ecological reliability of the method. The wellbore array is preliminarily prepared by pumping brines in small portions, after which leaching of the ice in the wellbore zone increases the injectivity of the well.

The injected brines, spreading over local voids, ultimately form a flooded zone 13. Experimental studies conducted by convention allow us to conditionally divide the section of toxic brines into the contaminated zone by mechanical particles 14; a zone for leaching ice and diluting brines 15; freezing zone of diluted brines 16.

In order to control the process of brine spreading in a permafrost array over the area around the absorbing hill 9, monitoring and observation wells 17 were drilled. In addition, the geophysical monitoring of the formation of the flooded zone was carried out. The main methods of control use the methods of transients and vertical electrical probing.

At the stage of preparation of the permafrost massif during the injection of highly mineralized brines, an increase in the level in the observation well of 17 to the low rates of its fall after the termination of downloads indicates that the near-well array is unprepared to receive injected brines. After leaching the ice and increasing the injectivity of the mine working 9, the water level in the control well 17 does not only rise, but gradually decreases.

Claims (2)

Invention Formula I. Method of storing toxic brines in permafrost conditions, including the collection and accumulation of brines in surface accumulators, the injection of brines into natural permafrost reservoirs through mining at the sections of the massif with increased fracturing, in the zones of deep faults - through mining developed above the permafrost soles, characterized in that five increasing storage efficiency by reducing the surface storage capacity and increasing the environmental reliability of brine storage, preprocessing the frozen reservoir adjacent to the mining development by batch injection into the brine production, and the injection of the latter takes place below the basis of erosion of the surface of the array before the brine spreading stops in the array after freezing. 2. A method according to claim I, characterized in that in the autumn-winter period, brines with concentration are jigged to prepare for the preparation of the adjacent array 3aj, J) brine concentration heated, and in the summer period brines heated by atmospheric air.